My grandad was a serious sort of a chap but the one person who could make him laugh was Charlie Williams – the black Yorkshire comedian. As far as I was concerned, this made Charlie an absolute magician. So when I was older, I found out where he lived and visited him. He was retired but I shook his hand and said thankyou for being such an important part of my childhood. I took his picture as a souvenir and that was how I started photographing comedians..

I met Johnny Vegas in 1999 just before he was big. He was doing a residency at the Citadel Club in St Helens – they were wonderful, crazy nights. He'd walk on stage in a really awful 1970s suit and do a show that was drunken and fabulous. I adored it. The crowd worshipped him even though they were utterly disgusted. Anyone foolish enough to heckle would be knocked to the ground – he was brilliant at that. His real name is Michael Pennington but he had created this Johnny Vegas character, a failed Butlins redcoat. He would lead incredible drunken singalongs, mixing in stories from his past. One infamous – and true – story was that one day he came home from school to find his dad cooking his rabbit.

I had arranged to photograph him as a fan, just for my portfolio. Within 10 minutes, I was shooting him in a wardrobe with a suitcase full of photocopied fivers. Then he posed naked, straddling a chair, Christine Keeler-style. That shot's never been exhibited, but some people have seen it: a while back, I gave away goody bags after a show to people who had travelled a long way. I included a small print of Johnny on the chair.

Then, about four years ago, he asked if I would photograph his wedding and do the cover of his autobiography. I was over at his house chatting about ideas when I noticed this latex head on a bookshelf. I was gobsmacked. The head had been made for an episode of his TV show Ideal, in which Johnny's character is decapitated. It arrived by courier in a cardboard box. I saw immediately that it would make a great surreal image. His eyes look as if they are just about to open.

It was important that the cover of the book encompassed the duality of Michael and Johnny: a photograph of his fake head did that perfectly. Johnny loved it, but it was rejected by the publisher because, not long before, a woman in Spain had been attacked in a supermarket – she had her head cut off. They felt it was inappropriate, given the book would be on sale in supermarkets.

So Johnny came to my house for a photo session. He hadn't played the character for about 18 months and he wasn't drinking. He had no choice but to become Johnny Vegas without alcohol, which had always been an important element of the act. It took a lot for him to get into a state, but in the end he was bawling and screaming – it was like watching Jekyll and Hyde or the Hulk. I found it uncomfortable and upsetting, but I did get two images that were used. Afterwards he said I had been edging towards the door.